Stef, Best glide speed will result in the greatest distance travelled for the altitude used (distance/altitude), minimum sink speed will keep the airplane aloft for the maximum amount of time and result in the slowest descent rate, which is nearly always found at max lift/drag on the drag curve.
The best way to fly the test profiles and determine both along with Vx and Vy climb speeds is a series of climbs and descents. I typically use 2000ft on each run to get more data points. First, you want to determine a course that will eliminate head/tailwind, ideally we’d do the test on a zero wind day but that isn’t always possible. In any case, a minimum amount of wind is best. I’ll climb 2000ft at stall speed + 5-10 kts to start then descend at the same speed. Then increase 5 or 10 knots and repeat until you are at projected Vy for climb and best glide +10-20 knots. If you have an EFIS (Garmin, Dynon, MGL, etc.) you can record the data and then use Flight Data Viewer from jasflyer.com to analyze your runs. If you don’t have an EFIS use pad and pen, GPS, and stopwatch to record time, rate, and distance data to climb and descent at each speed on your no-wind heading. Then you can calculate the Vx (shortest distance to reach finish altitude), Vy (shortest time to altitude) for climbs, Min Sink (lowest decent rate or greatest time to finish altitude), and Best Glide (greatest distance obtained). For the KR I would start about 65kts and work up to about 110kts with at least two runs at each speed. This should get you good data to work with if you really want to get exact numbers for your airplane. My 120hp Corvair powered KR came in at 14:1 glide ratio, Vx 68kts, Vy 80kts, min sink 70kts, best glide 78kts. Cheers, Adam Deem On Sat, Oct 3, 2026 at 2:50 AM Stef den Boer via KRnet <[email protected]> wrote: > Hi KR friends > My KR ( the PH-TDB) is now passing the 250 hours and I am stil so happy to > fly with her. > Yesterday I did the glide ratio test to give this numbers to my garmin > display. Now I have on the display a circle, this give the max distance I > can land without engine. > > Question for you is…did I do the test good? > Airplane was 1300 lbs > From mark longford website I took a glide speed of 78 kts > The average vertical time / speed for 1000FT was 1:05 min ( we did 3 > runs, 1:07 , 1:04 , 1:05) > > I am curieus did I do this test oke and what are your numbers? > > > Regards and keep up the building spirit….it is so good to fly your own > bird. > Stef > > > > > > > Steph and his dad are building the KR-2S see http://www.masttotaalconcept. > nl/kr2 > -- > KRnet mailing list > [email protected] > https://list.krnet.org/mailman/listinfo/krnet >
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